A. Field of the Invention
This invention relates generally to devices for the dispensing of material in measured amounts, and in particular for the controlled dosage of livestock.
B. Background of the Invention
The controlled dispensing of material has been necessary in a number of fields, including the dispensing of animal health care products, adhesives, paints, food and any place that it is necessary that measured amounts of material are dispensed.
One sure method of measuring the amount of dispensed material is to measure each independent dose. Unfortunately, the measurement of each independent dose is time-consuming and since many materials which are to be dispensed display significant adhesive qualities, there is great waste in individually measuring each dose. The material adheres to the measuring recepticle and great amounts of material are lost.
It has been known for some time that material can be dispensed in a tube in which a nozzle is provided at one end, so that the material is squeezed or moved along the tube and dispensed through the nozzle. It can also be shown that if a diaphram is inserted in one end of the tube and pressed against the material that an amount is dispensed out the nozzle in relation to the distance that the diaphram is moved along the tube. If the tube is calibrated, the amount of material dispensed can be easily viewed.
It has been shown in the dispensing of materials such as caulking compounds, that a rod attached to a diaphram may be advanced along the tube by a ratchet mechanism as long as constant pressure is applied to a lever arm advancing the rod. If, for example, in the treatment of an animal health care problem, such as scowers in baby pigs, the medicine is placed in a tube and the diaphram is moved along at a pre-determined distance, the dosage of the medicine will be constant for each baby pig. Unfortunately, it is necessary to view the diaphram movement before and after each application. Conventional caulking guns and devices which dispense material in this fashion do not have a means for pre-selecting the movement of rod and diaphram travel.
Accordingly, a need exists for such an improvement in dispensing devices, so that the amount of material dispensed is uniform and constant for each application; that the dispensing of the material is accomplished without an individual pre-determined measurement for each single dose; that the tube or vessel holding the material does not have to be viewed for each independent dose, but rather that each single application can be accomplished with a single movement, and yet the dosages are constant and uniform. Also, there exists a need for a means for varying the amount of the dose to be established with each movement. The instant invention is directed toward that need.